Fingerprint recognition technology is used to realize identification by capturing fingerprint images of a person using optical fingerprint sensors and then determining whether the fingerprint images match those stored in a system before. Due to its convenience in use and uniqueness of human fingerprints, the fingerprint recognition technology has been widely applied to various fields, such as safety inspection field (for example, public security bureau or customs), entrance guard systems in buildings or consumption goods field (for example, personal computers or mobile phones).
Among fingerprint imaging modules used in the fingerprint recognition technology, there is a type of optical fingerprint imaging module which can be used to acquire fingerprint images of a human body. Specifically, incident light is generated by a light source and irradiates onto a surface of a finger. Based on the reflection of the finger, reflected light with fingerprint information is formed and received by an image sensor, so as to obtain a fingerprint image.
When the optical fingerprint imaging module is applied to a mobile phone or other mobile devices, the fingerprint imaging module becomes a part of appearance of the device. Therefore, there is a requirement on color of appearance of the sensor. The fingerprint imaging module needs to be colored to adapt appearance design of the device.
However, the color of the appearance and an imaging effect of the colored fingerprint imaging module in existing techniques need to be further improved.